New analysis from Avalere finds that accountable care organizations (ACOs) in the Medicare Shared Savings Program (MSSP) achieve higher savings for Medicare the longer they are in the program. ACOs in the MSSP for 4 or more years were responsible for nearly all of the program’s previously reported $314 million in savings in 2017, the first year in which the program generated savings. In the same analysis, Avalere found that the assumption of downside risk does not appear to be a reliable predictor of an ACO’s success.

The MSSP is Medicare’s largest alternative payment model, as part of a broader government effort to shift its healthcare payments away from a fee-for-service model. Since 2012, the MSSP has grown from 27 ACO participants to 561 in 2018. In 2018, 10.5 million Medicare beneficiaries received care through an ACO.